1. Field of the Invention
The present invention relates to a rechargeable electric shaver and more particularly relates to a highly safe rechargeable electric shaver which has waterproof properties.
2. Prior Art
A rechargeable electric shaver is repeatedly used by recharging a rechargeable battery installed inside the main body casing of the shaver. In such a rechargeable electric shaver, there are absolutely no problems in an ordinary recharging operation. However, if reverse charging is performed or if excessive charging is performed as a result of rapid charging, then problems arise. Oxygen gas and hydrogen gas generate inside the rechargeable battery by the charge-discharge reaction. Accordingly, a safety valve which releases gas to the outside of the rechargeable battery when the internal gas pressure rises to an abnormal level is disposed in the rechargeable battery.
However, in the case of a waterproof type electric shaver, the main body casing is formed as a structure that is sealed off from the outside in a watertight manner in order to waterproof various types of parts accommodated in the main body casing. Accordingly, the gas released from the rechargeable battery fills the interior of the main body casing, and a problem of ignition of the hydrogen gas by sparks from the motor has been encountered. Accordingly, in the case of waterproof type rechargeable electric shavers, a ventilation port is formed in the main body casing, and the main body casing is sealed in a watertight manner by closing the ventilation port with a gas-permeable sheet or the like, so that gas released inside the main body casing is discharged to the outside of the main body casing.
However, in such a structure, the discharge of the gas released from the rechargeable battery to the outside of the main body casing is hindered by the gas-permeable sheet, and the problem of ignition of the gas that accumulates inside the main body casing arises. So as to solve this problem, in the rechargeable electric shaver described in Japanese Patent Application Laid-Open (Kokai) No. S58-165884, a rechargeable battery compartment and a driving portion compartment that accommodates the motor are separated in an airtight manner using a sealing member, so that sparks do not ignite the gas.
The structure in which the rechargeable battery compartment that is a gas generation source and the driving portion compartment in which sparks might occurs are separated in an airtight manner as described above is effective in preventing ignition by sparks. However, when a partition wall is installed so that the partition member cuts across the interior of the main body casing in order to separate the rechargeable battery compartment and driving portion compartment in an airtight manner a problem arises. Disposition of parts inside the electric shaver is restricted.
Especially in the case of electric shavers in which its main body casing is in a curved shape, if a partition member is installed so that the partition member cuts across the interior of the main body casing, the degree of freedom with which parts can be installed therein is restricted, and the installation of such parts becomes difficult.
FIG. 2 shows an electric rotary shaver that has a curved main body casing. In this shaver, a cutter head 12 is detachably mounted on the upper portion of a main body casing 10, and outer cutters 14 are provided in this cutter head 12.
FIG. 3 shows the inside the main body casing 10 of the electric shaver of FIG. 2. The reference numeral 16 is a partition member, 18 is a rechargeable battery, and 20 is a motor. The partition member 16 is disposed so that this wall cuts across the main body casing 10, and the rechargeable battery compartment A and the driving portion compartment B in which the motor 20 are separated by the partition member 16.
Since the partition member 16 is installed so that the wall cuts across the interior space of the main body casing 10, the interior space of the main body casing 10 is divided into two by this partition member 16, and parts are installed in the respective spaces that are partitioned from each other by the partition member 16. In cases where a number of parts that are required for the control of the electric shaver are employed, these parts must be separately installed in the spaces that are partitioned from each other by the partition member 16. As a result, electrical connections must be made with the partition member 16 interposed, and a complicated structure in which electrical connections are made in the partition member 16 must be adopted.